christie



POWER TRANSMITTING CLUTCH MECHANISM Filed NOV. 18, 1950 4 Sheets-Sheet l www ya?,

ATTO R N EYS Feb. 7, 1956 c. D. CHRISTIE 2,733,795

POWER TRANSMITTING CLUTCH MECHANISM Filed Nov. 18. 1950 4 Sheets-Sheet 2 .II'L E12 IN V EN TOR.

CHESTER D. CH RISTFE ATTORNEYS Feb. 7, 1956 c. D. CHRISTIE 2,733,795

H CH NI INVENTOR. TER D. CHRI l BY i MQW/7M NEYS ATTO R Feb. 7, 1956 Q D CHR|5T|E 2,733,795

POWER TRANSMITTING CLUTCH MECHANISM Filed NOV. 18, 1950 4 Sheets-Sheet 4 /26 ze 2e INVENTOR.

CHESTER D. CH Rl STIE ATTORN EYS United States Patent() POWER TRANSMITTING CLUTCH MECHANISM Chester D. Christie, Beachwood Village, Ohio, assignor to Eaton Manufacturing Company, Cleveland, Ohio, a

corporation of Ohio Application November 18, 1950, Serial No. 196,491

4 Claims. (Cl. 192-67) This invention relates to power transmitting mechanisms and more particularly to clutching gear elements therefor.

Broad1`y,the invention comprehends the provision of clutching or braking gear mechanism wherein the engageable gear teeth of respective clutch gear members are each provided with mating inclined front faces and mating inclined sidefaces and with zero clearance or overlap therebetween such Athat engagement of the gears upon relative rotation in one direction is prevented whereas engagement'occurs therebetween at the slightest reversal in relative rotation.` Y

Although numerous clutching gear mechanisms have been devised none have heretofore positively prevented engagement between the respective clutching gear ,members thereof for either relative rotation in one direction or at zero relative speed therebetween such las is assured by the present mechanism.

Among the objects of the invention is the provision of I a clutching gear mechanism of novel structure and gear tooth form that isv relatively quiet and smooth inV operation com'pared to presently utilized gear mechanisms of a like nature that operates with less wear than presently used mechanisms through the elimination of severe clashing between the trailing edges of the mating teeth on the engageable gear elements of the mechanism, that prevents clutching engagement between the elements thereof during relative rotation in one direction and atvz'ero relative speed between the members when a provision is 'made for overlap relation between the front faces o f the gear teeth on one member and the entrance passages between the gear teeth on the other member, ,yet encourage engagementrat 4 the-slightest reversal in relative direction of rotation between the members and that prevents clutching engagement between the members thereof during relative rotation in one direction between the members when zerov clearance or no-overlap provision is made between the front faces of the gear'teethon the one member 'and the entrance passages between the-'gear teeth on the other` membe'ryet permit of possible engagement at zero relative speed in relative direction of rotation'between the members.

Other objectsand advantages of the invention willV appear from the following description taken in connection with the drawings forming'a part of the speciication, and` inwhich:

view of la "elu'tching"lgearr mechanism'jenibodying .the ining gear plate of the'mechanism of Fig.' 1;

- 1 ,.60 Fig." 1 'is"a'partial'eleyationand a p 'artialcross-sectional Fig. 3 is a cross-section view taken substantially Aalong;

lines 3-3 of Fig. 2;

Fig. 4 is a side elevation view of the Aclutchingl gear member of the mechanism of Fig. 1;

Figs. 5 through 7 arediagrammatic illustrations vshow A,are moved directly axially toward one another.

42,733,795 Patented Feb. 7, 1956 cumference of the mechanism of Fig. 1 indifferent posi- Similar reference characters indicate corresponding parts throughout the several views of the drawings.

The presently devised clutching or braking gear elements of power transmission mechanisms are directed at the provision of clutch gear teeth, of a clutching or braking gear element, of specific related shape and size to one another and the spaces between teeth that when mated with a similarly constructed clutching or braking gear element, depending on the desired controllable use thereof, a positive inhibition of locking engagement is assured therebetween for one direction of relative rotation between the elements whereas locking engagement therebetween is encouraged when the slightest reversal of relative rotation occurs between the elements. It is possible to permit locking engagement between the Velements at synchronization or zero relative speeds between the elements by providing no overlap or zero clearance for the entry of the respective teeth on one element into the spaces between the teeth on the other element when the elements Under conditions where overlap is provided the teeth cany not move axially directly into engagement with one anotherV that is the inclination provides for an increase in the width,

of the opening or spaces between the teeth from the crest to the base thereof with a converse greater width of the teeth at the crest than at the base. When in locked engagement the inclined side faces of the teeth become engaged and either a reaction or driving force is provided therebetween depending on whether the mechanism to which applied is utilized in a braking or clutching operation between the elements.

Aside from achieving a desiredcontrolled condition of operation between the' mating gear elements severe' clashing between the trailing edges or corners of -the mating teeth in a unidirectional blocking phase of operation of the mechanismis eliminated resulting in a reasonallly. quiet and smooth operation therebetween as wellas assur-I ing a prolonged life thereof.

Referring to the drawings for more specific details thereof 10 represents generally a clutching or braking gear mechanism comprising a 4shiftable or sliding clutchinggear' element 12 adapted under certain' prescribed operating conditions to have locking engagement with a 4'clutching gear element or plate 14.

The sliding element 12 is provided with an annular yoke receiving portion 16 within which an appropriate yoke 18|, i 's received eiective' through the pivotal action of the yoke about its pivotanchor 2 0 to shiftl the element `12 axially as desired forclutching or brakingengagement with the plate 14. v The element 12 has an external clutching gear 22 integral therewith of specific design, to be hereinafter defined, for locking engagement with an internal clutching or braking gear 24 of like design as gear 22.

I Whereas either one or both of the gears 22 and 24 may have driving or driven relation with gearing, shaftsor the like :such that either a braking or clutching locking' engagement isattained upo'n mating relation between the gears-thereof the illustrationl of Fig. 1 shows the plate 3 14 as a stationary member and element 12 as both a sliding and permissibly rotatable member- The teeth 26 of gears 22 and 24 as shown in circumferential development by Eigs. through 7 are of like conguration wherein each tooth has an inclinedA frontface 2S of"predeterminedv angularity, the angle of which is determined by the lift desired when the gearsxare not syn: chronized; ln addition to the inclination of the front face of each gear tooth, one side face 30 of eachl tooth is inclined away from a plane passing through thetaxis of the geartsaid inclination being on the side of the tooth at its greatest axial length or height. YWith the tooth being inclined on one side face 30 and having-its other side face 32 lying in a plane passing through the axis of the lgear, the tooth has, a greater circumferential width at its crest than at its base, wherein the side face 3 0 of the tooth converges from the crest to the base thereof inA relation to side face 32, the purpose of which will hereinafter appear. Thev angle of inclination on the side face of each tooth is determined upon the desired backlash when the gears are engaged, the clearance at the point of engagement and desired amount of overlap.

The overlap 34' shown by Fig. Sto be provided between the teeth on the engageable gears is determined by making the toothof such circumferential width at its crest andi the openings or spaces 36'of such width between the crests of' adjacent teeth that upon direct axial movement ofthe gear elements toward one another the peak fr ont face portion of the crest on one tooth of one gear willA abut the peak front face portion of a toothY on the other` gear.

This overlap condition must be regulated as` to maximum amount so that when the respective front faces are slid one upon the other in the relative direction of; rotation for the locking engagement of the gears 22 and 241 o f'- the elements 12 and 14,v the width along the inclined face of; the tooth is equal to'or less than the width ofthe opening, between the teeth on the mating gear,V lyingina plane of the frontface of the tooth that the toothof the other memberl slides across in moving to a` position for, entry be,- tween the teeth. It is toV be noted in view of the arrange ment of the teeth of each gear in circumfercntially spaced array that the openings or spaces 36`of one gear element are complementary` tothe teeth of the gear on, the other gear element for the appropriate reception therein of said, gearteeth in accordance with the predetermined' estab,- lished mode of'operationto occur between the elements.y f

If no overlap or zero clearance as shown by Fig, 8 provided between the entrance of the openings andthe Width of'tho tooth to. be received. therein, a, condition. of synchronizvation` o r z ero relative speed betweenv theA elle: ments could permitl ofl a locking', engagement between., the elements, that Ais, one. gear. couldv` he movodhirootly axially into engagementwiththe other geanibut would. be capable of positively inhibiting locking engagement; under onel predetermined condition of relative rotation, there between.

With reference to Fig. 5, assuming that ele1nen t,14fis y held' stationary and the element 12 isfrotated in the` direc tion o f' arrow A, any attempt` t0 cause axial movement off the element 12 toward engagementofgear 2 2 upon gear 24 will result in the front faces of the gearsridingup oneupon the other such that as the peak portions, 38. Offthel frontv facesl of the mating teeth pass. over eachother the,`

relativity ofmotion between elements 12 andl2l4 preventsv they gearsl from moving axially'into engagement whether or not-'an overlap 34 is-provided since by the time the gears are moved axially the relative motion therebetween as'- sumes-a sliding ofthe short heightfportionstt) ofthe front faces'of` the gear teeth upon one another.

Fig. 6 illustrates the condition of lockingengagement between the gears 22 and 24 of elements 12and-14lwherein the element` 12 has;reyersoditsl direction of rotation relative. to element the-front facesoitl1e.gearteethofl element` 1,2.V slide axially inwardlyl upon;;the,front;faces of: the gear teeth of element; 14VV whereupon asthelfaegpor?.

tions 40 of the gear teeth slide past each other the side faces ofthe teeth have comento engagement and through the provision of the teeth having a frontal face length equal to or less than the entrance opening between the side faces 30 and 32 of adjacent teeth on the gear of element 14 taken along the plane of inclination of the front face of the teeth of the gear of element 14.

Fig. 7 illustrates the final locking engagement relation between the elements 12 and 14 wherein the inclined side faces 30 are in reaction bearingV relation to one. another wherein because of the stationary relation of' element 14 the element 12 is inhibited from rotation until such time as it is, once again shifted axially` out, of engagementwith element 14.

It is to be noted in viewing the amountv of overlap 34 provided between the teeth of the gear elements 12 and 14 as shown by Fig. 5, that the side faces 32 of the teeth lie in a common plane and that, therefore no amount of axial' movement will provide engagement. between. the teeth: of. the gear elements even if the elements are operating; atr synchronization or zero relativer speed.y At'thesarne-time it will be immediately apparent. that by diminishingI the overlap to zero such as shown in Eig. 8,"it.be possible t0 effect an engagement between thegears. at synchronize:- tion.

Through the provision of a positive overlap itis self, evident that as the front facesfofI the teeth. of, gear ele,-v ment 12 move over the front faces` of the. teeth of` gear. element' 14 no clashing or grabbing of low height portion 40 cornersV of the f rontfacos: adjacent side, faces: 2- ooour thereby permitting, of. smoother and, quietos operation of the -elements relativey to lone another when uni-directional blocking. condition of OPration whichr in turn assures longer. eiotivo. operating I ifoI thereof.

Although the gear'el'ements" have, been dSClOSGd, with respect to. one specific forml of structural embodiment and applioatioh they are st lsooptihlf:- of. numerous Structural changes and applications withoutdeparting from thebasic fundamentals offstrnetureand operatiOlL akin; thereto and; are therefore to heV limited solely by. the` scope of' the ap4 pendedclaims wherein the, terms clutchor clutchingf are to be interpreted` in the all embracing denition to alsoirloludo broke or braking WhatI claim is:

1- A olhfohihs mechanism comprising a Bair ofohsase able Cylindrical." clutching elements. oooh trav-ihn o. plu:l rality of( haul-S,pacedI goor tooth, said teeth each having: ,front tages ihotihed. to. a plano. pernohdioolah to. the asis of the moohahism. Providing for" motiharelatoh between the front faces. ofi the toothy oi thel respectivo, olhtohiheelements alohaoommohplahos a sidefaoo lyihasohstam tiollrih a nl'oho passing through the. .axis ofthofolutohine mechanism. audio side face `iholihotl to ariane. passion through the axisotltho-olutohhe moohahismhdioihihefthe frohtfooo. fihe toothat the. pointofgreatosf axial-length: thereof, providing for. a greater width. ot thetooth otite' frohtflaoo. thonet its.base;said.tooth-.boing orovidedof'suoh. widthat theftont ,faces thereo and the speces.bet-weenthel teeth at the front face positions thereof being provided of; such widthy that the teethon. oneclutching` elementcannot enter into the spaces between the teeth' onr the other clutching, clement upon a. relativeN direct; axial mQVoment of the clutching element toward one another with; no relative rotation. existing., between: the olutohihs. elements ondolo that.toothLoaohe.olutohinao ont-omaha).

enter into the spaces between the teeth on `the otherA clutching element fon onev direction of relativoV totationf between the cooperative clutchingY elements whileu permitting movement of' the; teeth of the cooperative' clutch-` ing elements to enter the spaces betweennhe teethfof the" cooperativegcluthing elements for; ai reverseV directionof relative rotation therebetweeng., said?. tee/thv ofj'both clutching, elements-, being; identical in; size4 and shape-"andthe spaties;betweeni-theftceth.:onfbothtclutching-elrnentsbeingj i identicalintsizer and; shape.-

5 2. A mechanism according to claim 1 wherein the spaces between eachrrst side face and each inclined side face lying in a plane of the inclined surfaces of the teeth areof a width equal to or slightly greater than the width of the teeth along the inclined front faces thereof. p

3. A mechanism according to claim 1 wherein the front face portions of the teeth thereof are of such width that with the side faces of the teeth lying in a plane passing through the axis of the clutching mechanism being arranged in a plane common said side faces of both clutching elements, the front face portions of the teeth on the respective clutch elements will be in overlapping mating relation adjoining ythe inclined side faces thereof adjacent the greatest axial length of the teeth.

4. Av mechanism according to claim 3 wherein the spaces are of slightly greater width throughout their axial length than the teeth adapted to be received therein are throughout their axial length.

References Cited inthe file of this patent UNITED STATES PATENTS 1,163,085

Hardy Dec. 7, 1915 1,515,100 Foster Nov. 11, 1924 2,049,126 Mayback July 28, 1936 2,180,597 LeBus a Nov. 21, 1939 2,218,398 Jameson Oct. 15, 1940 2,499,954

Hook a Mar. 7, 1950 

